Method and apparatus for skin-packaging articles between film-on-film

ABSTRACT

There is provided a continuous motion skin-packaging machine and method for the production of air-evacuated see-through film-onfilm packages of products. One of the film layers is softened by heat and is contoured around the product. Also, provision may be made for the introduction of an inert fluid, for example, nitrogen, into the package after the removal of air therefrom.

United States Patent Zelnick [54] METHOD AND APPARATUS FOR SKIN-PACKAGING ARTICLES BETWEEN FILM-ON-FILM [72] Inventor: Seymour Zelnick,Orange, NJ.

[73] Assignee: Weldotron Corporation, Piscataway,

22 Filed: Feb. 19, 1971 21 Appl.No.: 116,769

[52] US. Cl. ..s3/22 A, 53/112 A 51 1111.01. ..B65b 31/04 [58] Field ofSearch ..53/22 A, 112 A [56] References Cited UNITED STATES PATENTS3,491,504 1/1970 Young et a] ..53/1l2 A X [451 Oct. 31, 1972 3,061,98411/1962 Mahaffy ..53/22 A Primary Examiner-Travis S. McGeheeAttorneyl-larry Cohen [57 ABSTRACT There is provided a continuous motionskin-packaging machine and method for the production of air evacuatedsee-through film-on-film packages of products. One of the film layers issoftened by heat and is contoured around the product. Also, provisionmay be made for the introduction of an inert fluid, for example,nitrogen, into the package after the removal of air therefrom. 1

11 Claims, 7 Drawing Figures PATENTEDncm 1972 SHEET 1 OF 2 INVENTORSEYMOUR ZELNICK ATTORNEY PATENTEDnmm I972 3,701. 229 sum 2 of 2 I I I LII FIG? INVENTOR.

SEYMOUR ZEL NICK 't? l l ATTORNEY METHOD AND APPARATUS FOR SKIN-PACKAGING ARTICLES BETWEEN FILM-ON- FILM BACKGROUND OF THE INVENTION l.Field of The Invention This invention relates to apparatus and a methodfor skin-packaging products on a continuous basis.

2. Description of The Prior Art There are, at present, several designapproaches to continuous motion skin-packaging machines which producethe conventional type of skin-packaging, namely, contour formed film ona porous board and so form and adhere the upper, preheated web of film.Another type, shown by my assignees US. Pat. No. 3,462,909, utilizeselectrostatic forces to contour form the upper, pre-heated web of filmand adhere it to the porous board.

However, neither of the above approaches is capable of producing thetype of package which is desired and required for many foodapplications, namely, a contour formed upper web of film adhered to anon-porous lower web of film. Also, the desired package should have theair removed therefrom. This type of package is desirable for thefollowing reasons:

l. The contour formed upper film enhances the appearance of the package.

2. The transparent lower film gives visibility from the bottom also,which is now a requirement for many meat packages.

3. The evacuation of air is a requirement for preservation.

SUMMARY OF THE INVENTION In accordance with the present invention theproducts are packaged on a continuous basis between companionthermoplastic see-through films, namely, between a contour formed filmadhered to a nonporous companion film whereby'the appearance of thepackage is enhanced and the product is completely visible between thetwo films. Further, in accordance with the present invention, air isremoved from the interior of the package in order to enhancepreservation of foods constituting the packaged products, and ifdesired, an inert fluid, for example, nitrogen, may be introduced in theinterior of the package in order to further enhance the preservation.The method and apparatus for providing packages of the above describedcharacter constitute the primary objects of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The. above and other objects, featuresand advantages of the invention will be apparent from the followingdescription considered in connection with the accompanying drawingsillustrating a presently preferred embodiment of the invention.

In The Drawings:

FIG. 1 is a side view, in elevation, of a packaging machine embodyingthe present invention;

FIG. 2 is a transverse view on the line 2-2 of FIG. 1;

FIG. 3 is a transverse view on the line 3-3 of FIG. 1;

FIG. 4 is a sectional view on the line 4-4 of FIG. 1;

FIG. 5 is a sectional view on the line 5-5 of FIG. 1;

FIG. 6 is a sectional view on the line 6-6 of FIG. 1; and

FIG. 7 is a sectional view of the line 7-7 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION In accordancewith the present invention, one of the film layers, here shown as thefilm layer 10 in FIG. 1, instead of being of continuous width, comprisestwo parts 12 which are separate from each otherand have overlappingportions 14,16 (FIG. 2). The product to be wrapped, indicated at 18, isplaced on a stainless steel dead pan 20 and is advanced by flights 22,which are driven by chain 23, onto the film layer 10 which is suppliedfrom the rolls 24 and is moved longitudinally by the upper run 25 of amotor driven conveyor belt 26. The film rolls 24 are spaced laterally ofeach other and the films 12 are directed toward each other in a knownway until they overlap as indicated in FIG. 2. The companion film layer28 is. supplied from roll 30 and is drawn from said roll by vacuum belts32 (FIG. 4) which ride on two vacuum plenums 34 which are connected to avacuum pump (not shown). The vacuum belts carry the film 28 through aheating chamber 36 and deposit it against the product and film carriedby belt 26 as the latter begins to enter the vacuum chamber hereinafterdescribed. The vacuum belts are driven by a motor 38 through gearreducer 40 and pulley belt 42. The heating chamber comprises an airblower 44 and an electrical resistance element 46 which supplies heatedair to the film layer 28 for softening saidfilm layer 28 whereby it iscontoured around the individual products in response to the action ofvacuum thereon, as hereinafter described, and by the electrostaticpinning forces which may be provided, as disclosed in the abovementioned US. Pat. No. 3,462,909, and applied at the point at which filmlayer 28 is deposited on film layer 10, as indicated at 47 in FIG. 1, toefiect a more rapid operation than that possible by reason of the effectof the vacuum chamber. Substantially con-' currently with the contouringof the film layer 28 it is heat sealed around the packages to film layer10. The heated air is recirculated to the inlet of blower 44 from thepassage 48.

In accordance with this invention and as above indicated, provision ismade for evacuating air from the packages which are conveyed insuccession longitudinally of the apparatus. For this purpose theapparatus comprises a vacuum chamber 50 which communicates with thevacuum pump 52. The vacuum chamber 50 has a longitudinally extendingslot 54 into which the flaps i.e., marginal side edge portions 14 and 16of the two web parts 12 project, and a longitudinally extending nozzle56 provides communication between the vacuum chamber 50 and the interiorof each package as it moves across the vacuum chamber. The conveyor 26comprises two laterally spaced belts 58 (FIG. 4) so that the spacebetween said belts, which are driven in any suitable way-by the shaft60, registers with slot 54 which provides communication between thevacuum chamber 50 and the interior of the packages. Squeeze rollers 62are provided at the inlet and outlet ends of the vacuum chamber 50 toprevent loss of vacuum in the chamber through said ends, it beingunderstood that the abutting ends 14 and 16 of the layers 12 (FIG. 7)squeezed together by the rollers 62 of an overall thickness sufiicientto close the inlet and outlet ends of vacuum chamber 50 while said ends14 and 16 pass into and out of said chamber.

The present invention also provides for the introduction of an inertgas, preferably nitrogen, to augment the preservation of food productspackaged in accordance with the invention. For this purpose a chamber 64is provided in tandem with the vacuum chamber 50 so that as the marginalportions 14 and 16 of the layer pass from the vacuum chamber, they movethrough the chamber 64 whereby the gas in said chamber is introductedinto said package, said gas being supplied to said chamber 64 by a pumpindicated at 66. Squeeze rollers indicated at 62, similar to the squeezerollers 62, engage the film portions 14 and 16 for closing the inlet andoutlet ends of the chamber 64 in the same way as the rollers 62 closethe inlet and outlet ends of vacuum chamber 50. After the marginal edgeportions 14 and 16 exit from the chamber 64 they are heat sealed to eachother by rollers 62, at the out end of said chamber, which areelectrically heated for this purpose, and said edge portions areflattened against each other by a driven roller 68 (FIG. 6). As thepackages move downstream of the roller 68, they are separated from eachother, by the operation of the orbital sealing and cutting deviceindicated at 70 in FIG. 1, and move on to the discharge conveyor 72. Thefunction of this orbital sealing and cutting device 70 is to seal andcut the continuously moving film without requiring interruption ofmovement of the film. There are many known methods and devices foraccomplishing this function, among which are those, for example, shownby US. Pat. Nos. 2,951,325 and 3,140,218.

If the gas introduction chamber 64 is omitted from the apparatus themarginal edge portions 14 and 16 are heat sealed to each other byrollers 62 at the outlet end of chamber 50, said rollers beingelectrically heated for that purpose.

While there has been shown and described the preferred embodiment of theinvention, it will be understood that the invention may be embodiedotherwise than as herein specifically illustrated or described, and thatin the illustrated embodiment certain changes in the details ofconstruction and in the form and arrangement of the parts may be madewithout departing from the underlying idea and principles of thisinvention within the scope of the appended claims. I

What is claimed is:

1. A method of packaging products, comprising inserting the products insuccession between two layers of see-through thermoplastic film,contouring one of said layers to said products, sealing the film layersto each other around the individual products, advancing the film layersand the products therebetween to a vacuum station, and subjecting theinterior of the packages to the action of the vacuum at said station.

2. A method according to claim 1, wherein an inert gas is introducedinto the packages after they are subjected to the action of the vacuum.

3. A method according to claim 1, wherein the one of said film layerscomprises two portions which are adapted to overlap each other laterallybut which are separated laterally at the vacuum station in order tosubject the interior of the package to the action of the vacuum, andoverlapping said portions to close the package after it is subjected tothe action of the vacuum.

4. A method according to claim 3, wherein an inert gas is introducedinto the packages following the vacuum treatment and before theoverlapping operation is performed.

5. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, said air-evacuating means being operable during the movementof said film layers with the products therebetween.

6. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, said air-evacuating means comprising a vacuum chamber having aslot through which confronting laterally spaced portions of one of saidfilm layers move longitudinally of the slot, and means disposed betweensaid confronting portions and providing communication between saidvacuum chamber and the interior of said packages.

7. Apparatus according to claim 6, wherein means are provided to overlapand heat-seal said portions of the film layers to each other whereby toseal the packages.

8. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, said air-evacuating means comprising a vacuum chamber having aslot through which confro nting laterally spaced portions of one of saidfilm layers move longitudinally of the slot, and means disposed betweensaid confronting portions and providing communication between saidvacuum chamber and the interior of said packages and wherein means areprovided for introducing an inert gas into said packages following theoperation of the air evacuation means.

9. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, said air-evacuating means comprising a vacuum chamber having aslot through which confronting laterally spaced portions of one of saidfilm layers move longitudinally of the slot, and means disposed betweensaid confronting portions and providing communication between saidvacuum chamber and the interior of said packages and wherein means areprovided for introducing an inert gas into said packages following theoperation of the air-evacuation means, and means to overlap andheat-seal said portions of the film layers to each other whereby to sealthe packages.

10. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, the means for moving one of said film layers in confrontingrelation to the other of said film layers comprising laterally spacedbelts engage able with said one film layer at the opposite longitudinalside edge portions of the latter, and means for heating and therebysoftening said one film layer to condition it for contouring around theproducts and for heat sealing said layers to each other around theindividual products during the movement of said layers by said belts,and vacuum chambers associated with said belts, respectively, forengaging said one film layer with said belts, respectively.

11. Apparatus according to claim 10, wherein said vacuum chambers arestationary and said belts are endless and are movable longitudinally ofsaid vacuum chambers, respectively.

1. A method of packaging products, comprising inserting the products insuccession between two layers of see-through thermoplastic film,contouring one of said layers to said products, sealing the film layersto each other around the individual products, advancing the film layersand the products therebetween to a vacuum station, and subjecting theinterior of the packages to the action of the vacuum at said station. 2.A method according to claim 1, wherein an inert gas is introduced intothe packages after they are subjected to the action of the vacuum.
 3. Amethod according to claim 1, wherein the one of said film layerscomprises two portions which are adapted to overlap each other laterallybut which are separated laterally at the vacuum station in order tosubject the interior of the package to the action of the vacuum, andoverlapping said portions to close the package after it is subjected tothe action of the vacuum.
 4. A method according to claim 3, wherein aninert gas is introduced into the packages following the vacuum treatmentand before the overlapping operation is performed.
 5. Apparatus forpackaging products between two layers of see-through film, comprisingmeans for moving said film layers in confronting relation in thedirection of their lengths with the products inserted in successionbetween said layers, means for contouring one of the film layers to theindividual products and said layers to each other around the individualproducts, and means for evacuating air from the sealed packages, saidair-evacuating means being operable during the movement of said filmlayers with the products therebetween.
 6. Apparatus for packagingproducts between two layers of see-through film, comprising means formoving said film layers in confronting relation in the direction oftheir lengths with the products inserted in succession between saidlayers, means for contouring one of the film layers to the individualproducts and said layers to each other around the individual products,and means for evacuating air from the sealed packages, saidair-evacuating means comprising a vacuum chamber having a slot throughwhich confronting laterally spaced portions of one of said film layersmove longitudinally of the slot, and means disposed between saidconfronting portions and providing communication between said vacuumchamber and the interior of said packages.
 7. Apparatus according toclaim 6, wherein means are provided to overlap and heat-seal saidportions of the film layers to each other whEreby to seal the packages.8. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, said air-evacuating means comprising a vacuum chamber having aslot through which confronting laterally spaced portions of one of saidfilm layers move longitudinally of the slot, and means disposed betweensaid confronting portions and providing communication between saidvacuum chamber and the interior of said packages and wherein means areprovided for introducing an inert gas into said packages following theoperation of the air evacuation means.
 9. Apparatus for packagingproducts between two layers of see-through film, comprising means formoving said film layers in confronting relation in the direction oftheir lengths with the products inserted in succession between saidlayers, means for contouring one of the film layers to the individualproducts and said layers to each other around the individual products,and means for evacuating air from the sealed packages, saidair-evacuating means comprising a vacuum chamber having a slot throughwhich confronting laterally spaced portions of one of said film layersmove longitudinally of the slot, and means disposed between saidconfronting portions and providing communication between said vacuumchamber and the interior of said packages and wherein means are providedfor introducing an inert gas into said packages following the operationof the air-evacuation means, and means to overlap and heat-seal saidportions of the film layers to each other whereby to seal the packages.10. Apparatus for packaging products between two layers of see-throughfilm, comprising means for moving said film layers in confrontingrelation in the direction of their lengths with the products inserted insuccession between said layers, means for contouring one of the filmlayers to the individual products and said layers to each other aroundthe individual products, and means for evacuating air from the sealedpackages, the means for moving one of said film layers in confrontingrelation to the other of said film layers comprising laterally spacedbelts engageable with said one film layer at the opposite longitudinalside edge portions of the latter, and means for heating and therebysoftening said one film layer to condition it for contouring around theproducts and for heat sealing said layers to each other around theindividual products during the movement of said layers by said belts,and vacuum chambers associated with said belts, respectively, forengaging said one film layer with said belts, respectively. 11.Apparatus according to claim 10, wherein said vacuum chambers arestationary and said belts are endless and are movable longitudinally ofsaid vacuum chambers, respectively.